On the hunt for spectrum

The bad news is that public safety may not get more than 10 MHz of spectrum in the 700 MHz band to call its own. The good news is that LTE is being developed for some 41 spectrum bands around the world, with software-defined chips capable of supporting a range of frequencies. And major operators around the world understand that their LTE networks won’t be deployed in just one band, either.

Current auctions for 4G spectrum are including not only the historically prime pieces of spectrum in lower bands, but also spectrum in higher bands like 2.5 GHz and 2.6 GHz. The higher pieces of spectrum also include unpaired spectrum, known as Time Division Duplex (TDD) spectrum, which often comes at a much cheaper price than paired spectrum, called Frequency Division Duplex (FDD).

As IPWireless’ Jon Hambidge mentions in the related story, it is looking more like operators will use lower frequency bands for widespread coverage and higher bands for capacity. His company recently teamed with Altair Semiconductor to develop a series of multiband modem products for this purpose.

Talk to major infrastructure vendors and they see the same trend. Motorola sees operators offering parallel services on FDD and TDD spectrum to optimize spectral efficiency, perhaps running video and other high-bandwidth services over the higher frequency TDD LTE network, while other data services are reserved for the FDD version of LTE.

I’ve mentioned before that public safety could get creative and perhaps do a deal with the likes of Clearwire for use of its 2.6 GHz spectrum. Moreover, cities like New York and Gillette, Wyo., have deployed IPWireless’ TD-CDMA technology using secured spectrum in the 2.5 GHz band.

But the government is also looking at a number of areas to free up spectrum both on a licensed and unlicensed basis. Perhaps the public-safety community should start rallying for some exclusive spectrum in other bands. President Obama issued a memorandum at the end of June directing federal agencies to make 500 MHz of spectrum available during the next decade for mobile and fixed wireless broadband communications.

In addition to considering reclamation of more broadcast airwaves, the FCC is looking at myriad spectrum possibilities, including the potential release of reserve spectrum the agency is sitting on as a result of the fact that some spectrum is riddled with interference and couldn’t be auctioned. The FCC is strongly encouraging further development of software-defined radio (SDR) to analyze the radio environment and decide the best spectrum band and protocol in which to transmit.

There has to be a play for public safety somewhere in there.

What do you think? Tell us in the comment box below.